Pin-puller.



1?. H. SKINNER.

` PIN PULLER.

APPLIUATION FILED mma, 1-912.

Patented sept.9,19131 `FRANK I-I. SKINNER, OF CI-IICAGO, ILLINOIS.

PIN-FULLER.

To all whom, t may concern:

Be it known that I, FRANK II. SKINNER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Pin --Pullers, of which the following is a specification.

My invention relates to` dental instruments and its object is to provide still further improvements in pin pulling devices heretofore invented by me for the purpose of removing crown-pins from the roots of teeth that have been crowned.

One of the principal objects of the present improvement is to provide a form of construction that will materially reduce the cost of manufacture, and ythat will make it possible to stamp the body of the instrument out of sheet metal.

Another object of the invention is to place the jaw-actuating screw, which is nearthe root of the tooth to be operat-ed upon, outside of the plane of movement of the jaw, thereby giving the operator a better accessibility tofthe screw in turning it. Further objects are a light and" neat construction, independenceof each jaw'so that one `jaw may be repaired or replaced without discarding the whole instrument, and a larger opening movement of the jaws by mounting both on pivots on which they may be swung away from' each other to any desired extent.

Vith the above-namedobjects in view, and such other advantages as may appear from the subjoined description, myk invention consists in the novel construction, combination and arrangement of parts hereinafter described in detail, illustrated in the accompanying drawing and incorporated in the appended claims.

In the drawing-Figure 1 is a perspective view of a substantially full-sized instrument embodying my invention. Fig. 2 is an enlarged side elevation. Fig. 3 is a vertical section. n

In the several views the post-actuating screw and the jaws are mounted on a crossbar having a central nut-portion 2 and hinge-knuckles 3 and 4. A post-actuating screw 5 has threaded engagement with the nut-portion 2 and is provided with a thumb-piece 6. On the knucklesl 3 and 4, in slots 7 and 8 thereof, are pivoted a pair of sheet-metal jaws 9 and 10 which have inwardly bent beaks 11 and 12 with i Speeication of Letters Patent.

` Application tiled February 3, 1912.

'Patented Sept, 1913. Serial No. 675,299.

serrated faces as shown in Fig. 3. On` the inner end of the screw 5 is swiveled a forked post consisting of a stripy of metal bent upon itself to form prongs 13 and 14. These prongs are supported upon each other to prevent their spreading apart near the beaks ofthe jaws, by a bridge-piece or rivet 15. On the jaws are struck-out ears 16 and 17, the former forming a stop Vagainst which'a shoulder 18 of a screw 19 bears. This screw has a reduced threaded portion 20 which has threaded engagement with the ear 17. Athumb-piece 21 completes this screw. 22 and 23 are the pivots upon which the jaws swing, and 24 is the swivelconnection between the screw 5 and the post. A root of a tooth to be operated upon is represented by dotted lines in Fig.

2 and a pin 26 cemented into said root and about to be ,withdrawn by the instrument is shown in the grip of the beaks of the jaws which have been clamped upon the pin by turning the screw 19.

In operation the projecting portion of the crown-pin 26 is withdrawn by turning the screw 5 to advance the post or prongs against the root 26. The jaws thus effect a pulling st-rain upon the pin while the post pushes against the root. In this manner the crown-pin may be removed without subjecting a patient to any pain or strain.

I'claim as my inventionl. In a pin puller, the combination with i a cross-bar, of a pair Vof jaws pivotally mounted in said cross-bar, a post coperating with said jaws, a screw having threaded engagement with said cross-bar and swiveled to said post, and a screw actuating said jaws. Y

2. In a pin puller, the combination with a cross-bar of a pair of jaws pivoted to the ends of said cross-bar, a Vscrew having threaded engagement with said cross-bar intermediate of said jaws, a post movable bent out portions forming ears Vto be en' gaged by a screw, a screw having threaded engagement with one 4of said ears and having a shoulder bearing against the other of said ears, a longitudinally movable post, and a screw swiveled to said post and having threaded engagement with said crossbar.

5. The Combination with a cross-bar, of a pair of sheet-metal aWs hinged to saidV cross-bar, a post bent upon itself and'having prongs which engage both sides of the v a screw arranged at one side of said jaws y for actuating same.

In testimony whereof I have hereunto vset my hand in the presence of two subseribing Witnesses.

FRANK H. SKINNER.

. Witnesses:

C. W. WTAHLGREN, Y J. W. BEGKSTROM.

Copies of: this patent' may be obtained for :ve cents each, by addressing the Commissioner of Patents.

' Washington, 1D. C. 

